package Views;

/*
 * SWView.java
 * This file contains the abstract view of a Stopwatch2
 * Created on February 9, 2002
 *
 * @author  Stuart Hansen
 * @version
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;

// The SWView class is the base class for all views of the stopwatch
public abstract class SWView extends JFrame implements PropertyChangeListener {
    
    public ViewState vstate;     // the view state is frozen or updating
    public JButton lap;          // the lap button

    // The constructor 
    public SWView (String displayName) {
	super(displayName);
        Container c = getContentPane();
        c.setLayout(null);

        lap = new JButton("Lap");
        lap.addActionListener(new lapController());
        lap.setBounds(25, 25, 60, 30);
        c.add(lap);
        vstate = new Updating();
    }
    
    // Views vary by how they display the time
    // Hence, this method is abstract.
    abstract protected void setDisplayTime (long timeArg);    

    
    // lapController sits between the button and the view
    public class lapController extends AbstractAction {
        public void actionPerformed (ActionEvent e) {
            vstate.lapPushed();
        }
    }


    // View State is the state of the display
    // The display is either updating or frozen
    interface ViewState {
        public void lapPushed();
        public void updateDisplayTime(long time);
    }
           
    // When updating, the display changes time with each
    // change to the stopwatch's time
    public class Updating implements ViewState {

	// The method that responds to the lap button
        public void lapPushed() {
            vstate = new Frozen();
        }

	// The method that updates the display
        public void updateDisplayTime(long time) {
            setDisplayTime(time);
        }
    }
    
    // When frozen an earlier time is displayed
    public class Frozen implements ViewState {

	// the method that responds to the lap button
        public void lapPushed() {
            vstate = new Updating();

	    // When the stopwatch enters the updating mode, it
            // fires a requestTime event so it can set the current time
            firePropertyChange("requestTime", new Long(0), new Long(1));
        }
	
	// When frozen the time is not updated
        public void updateDisplayTime(long time) { }
    }   

    // This method receives the events from the stopwatch and dispatches them
    // to the state
    public void propertyChange (PropertyChangeEvent evt) {
        vstate.updateDisplayTime(((Long)evt.getNewValue()).longValue());
    }     
}